Display Device for Personal Immersive Device

ABSTRACT

A display device for virtual reality. A first display panel comprises a first pixel row having a first end and a second end that is closer to the second display panel than the first end. The first pixel row has a first arrangement of unit pixels that alternate between a first unit pixel type and a second unit pixel type. A second display panel comprises a second pixel row aligned with the first pixel row and having a third end and a fourth end that is further from the first display panel than the third end. A first unit pixel at the first end of the first pixel row is the first unit pixel type, and a second unit pixel at the third end of the second pixel row is the second unit pixel type.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119(a)to Republic of Korea Patent Application No. 10-2015-0191800 filed onDec. 31, 2015, the entire contents of which is incorporated herein byreference for all purposes as if fully set forth herein.

BACKGROUND

Field of the Disclosure

The present disclosure relates to a display device for a personalimmersive device implementing virtual reality or augmented reality.

Discussion of the Related Art

Technologies for virtual reality or augmented reality (hereinafter,commonly referred to as “virtual reality”) have been applied to adefense field, an architecture field, a tourist field, a film field, amultimedia field, a game field, and the like. Virtual reality means aspecific environment or a specific situation allowing a user to feel asa real environment using a stereoscopic image technology.

The virtual reality technology has been applied to personal immersivedevices, so as to maximize the immersion of the virtual reality.Examples of the personal immersive device include a head mounted display(HMD), a face mounted display (FMD), and an eye glasses-type display(EGD).

Because the user wears the personal immersive device on his or her faceor head, a distance between the user's eyes and the screen is veryshort. For this reason, the personal immersive device is implemented asan organic light emitting diode (OLED) display having a self-emissionstructure. Further, the personal immersive device has used a pentilematrix scheme, in which a total of four subpixels (for example, red (R),green (G), blue (B), and green (G) subpixels) form two unit pixels,instead of a related art pixel structure, in which a total of three red,green, and blue subpixels form a unit pixel.

However, when a pixel structure of the pentile matrix scheme is appliedto the personal immersive device, and a first OLED display panel, onwhich a left eye input is displayed, and a second OLED display panel, onwhich a right eye input is displayed, represent a specific color, thespecific color is not represented on some of four unit pixels. Hence,there was a problem of a reduction in pixel density of each color.

This is described in detail below with reference to FIG. 1.

FIG. 1 illustrates a problem of a pixel array applied to a related artpersonal immersive device.

Referring to FIG. 1, R, B, G, and B subpixels are arranged on a firstrow of a pixel array of a first OLED display panel, to which a left eyeimage is input, in the order named, and G, B, R, and B subpixels arearranged on a second row of the pixel array in the order named. Further,R, B, G, and B subpixels are arranged on a first row of a pixel array ofa second OLED display panel, to which a right eye image is input, in theorder named in the same manner as the first row of the pixel array ofthe first OLED display panel, and G, B, R, and B subpixels are arrangedon a second row of the pixel array in the order named in the same manneras the second row of the pixel array of the first OLED display panel.

The left eye image received through a left eye of a human being and theright eye image received through a right eye of the human being arecombined in a brain of the human being. Hence, two adjacent unit pixelson the first row are recognized as RBGB, and two adjacent unit pixels onthe second row are recognized as GBRB.

Thus, two red colors, two green colors, and two blue colors arerecognized from the four unit pixels on the first and second rows.Accordingly, the four unit pixels recognize only one half of the colorswhich four R, G and B unit pixels recognize.

In the related art personal immersive device, because the distancebetween the screen and the user's eyes is very short, pixel density ofthe color displayed on the screen is reduced.

SUMMARY

In one embodiment, a display device for virtual reality is disclosed.The display device comprises a first display panel for displaying animage for a left eye and a second display panel for displaying an imagefor a right eye. The first display panel comprises a first pixel rowhaving a first end and a second end that is closer to the second displaypanel than the first end. The first pixel row has a first arrangement ofunit pixels that alternate between a first unit pixel type and a secondunit pixel type. The first unit pixel type comprises subpixels of afirst color and a second color but not a third color, and the secondunit pixel type comprises subpixels of the third color and the secondcolor but not the first color. The second display panel comprises asecond pixel row aligned with the first pixel row and having a third endand a fourth end that is further from the first display panel than thethird end. The second pixel row has a second arrangement of unit pixelsthat alternate between the second unit pixel type and the first unitpixel type. A first unit pixel at the first end of the first pixel rowis the first unit pixel type, and a second unit pixel at the third endof the second pixel row is the second unit pixel type.

In one embodiment, the first unit pixel type comprises subpixels of ared color and a blue color but not a green color, and the second unitpixel type comprises subpixels of the green color and the blue color butnot the red color. In one embodiment, the first unit pixel typecomprises subpixels of a red color and a green color but not a bluecolor, and the second unit pixel type comprises subpixels of the bluecolor and the green color but not the red color. In one embodiment, thefirst unit pixel type comprises subpixels of a green color and a redcolor but not a blue color, and the second unit pixel type comprisessubpixels of the blue color and the red color but not the green color.

In one embodiment, the first display panel comprises a third pixel rowhaving the second arrangement of unit pixels, the third pixel row havinga third unit pixel of the second unit pixel type. The third unit pixelis in a same pixel column as the first unit pixel of the first pixelrow. The second display panel comprises a fourth pixel row having thefirst arrangement of unit pixels, the fourth pixel row having a fourthunit pixel of the first unit pixel type. The fourth unit pixel is in asame pixel column as the second unit pixel of the second pixel row.

In another embodiment, a display device for virtual reality isdisclosed. The display device comprises a first display panel fordisplaying an image for a left eye and a second display panel fordisplaying an image for a right eye. The first display panel and thesecond display panel both have a mix of unit pixels that include a firstunit pixel type and a second unit pixel type. The first unit pixel typecomprises subpixels of a first color and a second color but not a thirdcolor, and the second unit pixel type comprises subpixels of the thirdcolor and the second color but not the first color. The first displaypanel comprises a first pixel row having a first end and a second endthat is closer to the second display panel than the first end. Thesecond display panel comprises a second pixel row aligned with the firstpixel row and having a third end and a fourth end that is further fromthe first display panel than the third end. A first unit pixel at thefirst end of the first pixel row is the first unit pixel type, and asecond unit pixel at the third end of the second pixel row is the secondunit pixel type.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 illustrates a problem of a pixel array applied to a related artpersonal immersive device;

FIG. 2 is an exploded perspective view showing a personal immersivedevice according to an exemplary embodiment of the invention;

FIG. 3 shows first and second display panels of a display module shownin FIG. 2;

FIG. 4 illustrates a distance between first and second display panelsshown in FIG. 3;

FIG. 5 is a graph showing a response time of an n-type metal oxidesemiconductor field effect transistor (MOSFET) and a response time of ap-type MOSFET;

FIG. 6 is a block diagram showing configuration of a display panel shownin FIG. 3;

FIG. 7 schematically illustrates a portion of a pixel array shown inFIG. 6;

FIG. 8 is an equivalent circuit diagram showing an example of a pixelcircuit;

FIG. 9 is a waveform diagram illustrating signals input to a pixel shownin FIG. 8;

FIG. 10 is a waveform diagram illustrating a duty driving method of apixel circuit according to an exemplary embodiment of the invention;

FIG. 11 illustrates a BDI effect in a duty driving method of a pixelcircuit according to an exemplary embodiment of the invention;

FIG. 12 illustrates a principle, in which data of a pixel is maintainedduring one frame period without additional data addressing;

FIG. 13A shows a first example of pixel arrays of first and seconddisplay panels of a display device for a personal immersive deviceaccording to an exemplary embodiment of the invention;

FIG. 13B illustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel arrays of FIG. 13A;

FIG. 14A shows a second example of pixel arrays of first and seconddisplay panels of a display device for a personal immersive deviceaccording to an exemplary embodiment of the invention;

FIG. 14B illustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel arrays of FIG. 14A;

FIG. 15A shows a third example of pixel arrays of first and seconddisplay panels of a display device for a personal immersive deviceaccording to an exemplary embodiment of the invention; and

FIG. 15B illustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel arrays of FIG. 15A.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the invention,examples of which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts. It will be paid attentionthat detailed description of known arts will be omitted if it isdetermined that the arts can mislead the embodiments of the invention.

Referring to FIG. 2, a personal immersive device according to anexemplary embodiment of the invention includes a lens module 12, adisplay module 13, a main board 14, a headgear 11, a side frame 15, afront cover 16, and the like.

The display module 13 includes a display panel driving circuit fordriving each of two display panels and displays an input image receivedfrom the main board 14. The display panels include a first display panela user watches with his or her left eye and a second display panel theuser watches with his/her right eye. The display module 13 displaysimage data received from the main board 14 on the display panels. Theimage data may be two-dimensional (2D) or three-dimensional (3D) imagedata implementing virtual reality (VR) video images or augmented reality(AR) video images. The display module 13 may display various informationreceived from the main board 14 as texts, symbols, etc.

The lens module 12 includes extreme-wide-angle lenses (i.e., a pair offisheye lenses) for widening an angle of view between the user's leftand right eyes. The pair of fisheye lenses include a left eye lensdisposed in front of the first display panel and a right eye lensdisposed in front of the second display panel.

The main board 14 includes a processor that executes virtual realitysoftware and supplies a left eye image and a right eye image to thedisplay module 13. The main board 14 further includes an interfacemodule connected to an external device, a sensor module, and the like.The interface module is connected to the external device through aninterface such as universal serial bus (USB) and high definitionmultimedia interface (HDMI). The sensor module includes a gyro sensor,an acceleration sensor, and the like. The processor of the main board 14corrects left eye image data and right eye image data in response to anoutput signal of the sensor module and transmits left eye image data andright eye image data of an input image received through the interfacemodule to the display module 13. The processor of the main board 14 mayproduce a left eye image and a right eye image suitable for a resolutionof the display panel based on the result of an analysis of depthinformation of a 2D image and may transmit the left eye image and theright eye image to the display module 13.

The headgear 11 includes a back cover exposing the fisheye lenses and aband connected to the back cover. The back cover of the headgear 11, theside frame 15, and the front cover 16 are assembled to secure an innerspace, in which components of the personal immersive device aredisposed, and to protect the components. The components include the lensmodule 12, the display module 13, and the main board 14. The band isconnected to the back cover. The user wears the personal immersivedevice on his/her head using the band. When the user wears the personalimmersive device on his/her head, he/she watches the different displaypanels (i.e., the first and second display panels) with his/her left andlight eyes through the fisheye lenses.

The side frame 15 is fixed between the headgear 11 and the front cover16 and secures a gap of the inner space, in which the lens module 12,the display module 13, and the main board 14 are disposed. The frontcover 16 is disposed at a front surface of the personal immersivedevice.

The personal immersive device according to the embodiment of theinvention may be implemented as a head mounted display (HMD) shown inFIG. 2, but is not limited to FIG. 2. For example, the embodiment of theinvention may be implemented as an eye glasses-type display (EGD).

FIG. 3 shows first and second display panels PNL1 and PNL2 of thedisplay module 13 shown in FIG. 2. FIG. 4 illustrates a distance betweenthe first and second display panels PNL1 and PNL2 shown in FIG. 3. Eachof the first and second display panels PNL1 and PNL2 is implemented asan organic light emitting diode (OLED) display panel having a fastresponse time, excellent color reproduction characteristic, andexcellent viewing angle characteristic. In case of the EGD, the firstand second display panels PNL1 and PNL2 may be implemented as atransparent OLED display panel.

Referring to FIGS. 3 and 4, the first and second display panels PNL1 andPNL2 are separately manufactured and are disposed to be separated fromeach other on the display module 13. At least a portion of the displaypanel driving circuit may be disposed between the first and seconddisplay panels PNL1 and PNL2. In FIG. 3, “DIC (drive integratedcircuit)” is an integrated circuit (IC) chip, into which a timingcontroller 110 and a data driver 102 shown in FIG. 6 are integrated. GIP(gate-in panel)” is a circuit, into which a gate driver 104 and anemission (abbreviated to “EM”) driver 106 shown in FIG. 6 and a pixelarray are integrated on the same substrate.

A distance Lp between a center of a pixel array AA of the first displaypanel PNL1 and a center of a pixel array AA of the second display panelPNL2 may be substantially the same as a distance Le between both eyes ofthe user. The distance Lp between the center of the pixel array AA ofthe first display panel PNL1 and the center of the pixel array AA of thesecond display panel PNL2 may be set to Le±α. The distance Le betweenboth eyes of the user is a distance between a pupil of the left eye anda pupil of the right eye and is about 6.5 cm. The distance Le mayslightly vary depending on a difference between individuals. “α” is amargin designed in consideration of the display panel driving circuit(for example, GIP of FIG. 2) disposed between the first and seconddisplay panels PNL1 and PNL2, a process deviation, etc. and may be setto 10% of Le.

The pixel array AA of each of the first and second display panels PNL1and PNL2 has a landscape type aspect ratio, in which a length in ahorizontal direction x is longer than a length in a vertical directiony, in consideration of a vertical viewing angle and a horizontal viewingangle. In the personal immersive device, an improvement effect of theviewing angle when increasing the horizontal viewing angle is greaterthan an improvement effect of the viewing angle when increasing thevertical viewing angle. The embodiment of the invention manufactureseach of the first and second display panels PNL1 and PNL2 as a landscapetype OLED display panel, so as to maximize the horizontal viewing anglein the personal immersive device.

In the landscape type aspect ratio, the number of pixels in thehorizontal direction x is more than the number of pixels in the verticaldirection y, and the length in the horizontal direction x is longer thanthe length in the vertical direction y. Further, in a portrait typeaspect ratio, the number of pixels in the vertical direction y is morethan the number of pixels in the horizontal direction x, and a length inthe vertical direction y is longer than a length in the horizontaldirection x.

The present inventors conducted an experiment on a stereoscopic feeling,an immersion, and a fatigue the user feels while changing types of thedisplay panel of the personal immersive device. According to the resultof the experiment, as shown in FIG. 4, when the pixel arrays of thefirst and second display panels PNL1 and PNL2 were separated from eachother by the distance between both eyes of the user, the presentinventors confirmed that the stereoscopic feeling the user feels wasgreatly improved. When the pixel arrays of the first and second displaypanels PNL1 and PNL2 are separated from each other and the distancebetween the centers of the pixel arrays of the first and second displaypanels PNL1 and PNL2 is the same as the distance between the left eyeand the right eye of the user, the viewing angle widens and a largeimprovement effect of the stereoscopic feeling is obtained. Further, thestereoscopic feeling the user feels is better in the landscape typeaspect ratio than the portrait type aspect ratio. The embodiment of theinvention can improve the stereoscopic feeling by separately disposing alandscape type display panel for left eye and a landscape type displaypanel for right eye at the personal immersive device.

The first and second display panels PNL1 and PNL2 may be separatelymanufactured on the substrates and may be separately disposed on thedisplay module 13. In another embodiment, the first and second displaypanels PNL1 and PNL2 may be separated pixel arrays AA on the samesubstrate, respectively. In this instance, the first display panel PNL1may indicate the first pixel array AA, on which the left eye image isdisplayed, and the second display panel PNL2 may indicate the secondpixel array AA, on which the right eye image is displayed.

In the personal immersive device, the fisheye lens exists between theuser's eye and the display panel, and a distance between the user's eyeand the display panel is as short as several centimeters. When the userwatches an image reproduced on the display panels PNL1 and PNL2 throughthe fisheye lenses, the user watches an image which is four to fivetimes larger than the size of a real screen displayed on the displaypanels PNL1 and PNL2. When a resolution of the display panel is low andused in an environment in which proximity between the user's eye and theimage and the fisheye lens are applied, a non-emission area of thepixels increases. Hence, a screen door effect increases, and theimmersion is reduced. The pixel array of each of the first and seconddisplay panels PNL1 and PNL2 has a resolution equal to or greater thanQHD (quad high definition) resolution (1440□1280), a pixel density equalto or greater than 500 ppi (pixels per inch), and a pixel aperture ratioequal to or greater than 14%, so as to increase the immersion of thepersonal immersive device. In the QHD resolution 1440□1280, “1440” isthe number of pixels of the pixel array in the horizontal direction x,and “1280” is the number of pixels of the pixel array in the verticaldirection y. The pixel array AA may have the pixel density of 500 ppi to600 ppi and the pixel aperture ratio of 14% to 20%, considering atechnology level of the producible OLED display panels.

When the personal immersive device displays a 3D motion picture, anincrease in a total latency may lead to screen retention or motion blur.The screen retention or the motion blur of the 3D motion picture reducesthe quality of the 3D motion picture and also increases a fatigue of theuser. The total latency is time adding a system processing time requiredto process data through the main board 14 and transmit the data to thedisplay module 13 to a delay time of the display module 13. The delaytime of the display module 13 is time adding a frame delay time, atwhich an input image is delayed during one frame period, to a responsetime of the pixels.

The embodiment of the invention reduces the fatigue of the user byreducing the response time of the pixels and increasing a frame rate (ora refresh rate) when the personal immersive device displays the 3Dmotion picture. To this end, the embodiment of the inventionmanufactures switching elements and driving elements of the pixels ofeach of the display panels PNL1 and PNL2 as an n-type metal oxidesemiconductor field effect transistor (MOSFET). Hence, the embodiment ofthe invention reduces a response time of a pixel circuit within 2 msecand increases the frame rate to a value equal to or greater than 90 Hz,shortening a data update cycle. When the frame rate is 90 Hz, the dataupdate cycle (i.e., one frame period) is approximately 11.1 msec. Thus,the embodiment of the invention reduces the delay time of the displaymodule 13 of the personal immersive device to about 13 msec and canreduce the total latency to a level equal to or less than 25 msec. Dataof the input image is addressed to the pixels through the data updatecycle.

FIG. 5 is a graph showing a response time of an n-type MOSFET and aresponse time of a p-type MOSFET. In FIG. 5, “4T2C” indicates a responsetime of a pixel circuit (refer to FIG. 8) including four n-type MOSFETsand two capacitors, and “6T1C” indicates a response time of a pixelcircuit (not shown) including six n-type MOSFETs and one capacitor.Further, in FIG. 5, A, B, and C are characters used to distinguishapplied models.

Referring to FIG. 5, the pixel circuit using the n-type MOSFET rapidlyincreases a luminance of the pixel to a luminance equal to or greaterthan 90% of a target luminance within 2 msec at a frame rate of 60 Hz.Thus, the pixel circuit using the n-type MOSFETs has a response timewithin 2 msec which is much shorter than one frame period (about 16.67msec). On the other hand, the pixel circuit using p-type MOSFETs mayrise a luminance of the pixel to a luminance equal to or greater than90% of a target luminance at a frame rate of 60 Hz after three frameperiods (about (16.67×3) msec) passed. Therefore, a response time isequal to or greater than three frame periods.

The embodiment of the invention duty-drives each of the display panelsPNL1 and PNL2 and controls a duty ratio of the pixels to a value equalto or less than 50% when the personal immersive device displays the 3Dmotion picture. Hence, the embodiment of the invention can furtherreduce the fatigue of the user using a black data insertion (BDI)effect. The duty ratio of the pixels is a percentage of an emission timeof the pixels with respect to a given emission time. For example, thefact that the pixels emit light at a duty ratio equal to or less than50% when a given emission time is one frame period means that the pixelsemit light for time equal to or less than one half of one frame period.The duty-drive of the pixels can obtain an improvement of the motionblur and a reduction in an image persistence time using the BDI effectand can prevent the image retention and a flicker. Further, theduty-drive of the pixels can reduce the fatigue of the user watching the3D motion picture by reducing an amount of current of the pixel at a lowgray level.

FIG. 6 is a block diagram showing configuration of the display panelshown in FIG. 3. FIG. 7 schematically illustrates a portion of a pixelarray shown in FIG. 6. FIG. 8 is an equivalent circuit diagram showingan example of a pixel circuit. FIG. 9 is a waveform diagram illustratingsignals input to a pixel shown in FIG. 8.

Referring to FIGS. 6 to 9, each of the first and second display panelsPNL1 and PNL2 according to the embodiment of the invention includes thepixel array AA displaying an input image and the display panel drivingcircuit for writing data of the input image on the pixel array AA. Thedisplay panel driving circuit includes a data driver 102, a gate driver104, an (abbreviated to “EM”) driver 106, and a timing controller 110.The display panel driving circuit further includes a power circuit (notshown). The power circuit generates electric power required to drive thedata driver 102, the gate driver 104, the EM driver 106, the timingcontroller 110, and the display panels PNL1 and PNL2. The first andsecond display panels PNL1 and PNL2 may share at least a portion (forexample, the timing controller 110 of FIG. 6) of the display paneldriving circuit with each other. The display panel driving circuitaddresses data to pixels 10 of the display panels PNL1 and PNL2 at ahigh frame rate equal to or greater than 90 Hz and writes the data onthe pixels 10.

A plurality of data lines 11 and a plurality of gate lines 12 a, 12 b,and 12 c cross each other on the pixel array AA, and the pixels 10 arearranged in a matrix form. The pixel array AA includes a referencevoltage line (hereinafter referred to as “REF line”) 16 commonlyconnected to the pixels 10 and a VDD line (not shown) used to supply ahigh potential driving voltage VDD to the pixels 10. A predeterminedinitialization voltage Vini may be supplied to the pixels 10 through theREF line 16.

The gate lines 12 a, 12 b, and 12 c include a plurality of first scanlines 12 a supplied with a first scan pulse SCAN1, a plurality of secondscan lines 12 b supplied with a second scan pulse SCAN2, and a pluralityof EM signal lines 12 c supplied with an EM signal EM.

Each pixel 10 includes a red subpixel, a green subpixel, and a bluesubpixel for color representation. Each pixel 10 may further include awhite subpixel. One data line 11, the gate lines 12 a, 12 b, and 12 c,the REF line 16, the VDD line, etc. are connected to each pixel 10.

One frame period is divided into a scanning period, in which data isaddressed to the pixels 10 and data of the input image is written oneach pixel 10, and a duty driving period, in which the pixels 10 emitlight at a predetermined duty ratio in response to the AC EM signal EMafter the scanning period. The AC EM signal EM is generated at a dutyratio equal to or less than 50% during the duty driving period andcauses the pixels 10 to emit light at the duty ratio equal to or lessthan 50%. Because the scanning period is about one horizontal period,the duty driving period occupies most of one frame period. Capacitors ofthe pixels 10 are charged with a data voltage during the scanningperiod. The pixels 10 repeatedly perform an emission operation (or aturn-on operation) and a non-emission operation (or a turn-offoperation) in response to the AC EM signal EM. Each pixel 10 repeatedlyperforms the turn-on operation and the turn-off operation during oneframe period and emits light at the duty ratio equal to or less than50%. The pixels 10 are turned off and then emit light using the datavoltage charged to the capacitors. Therefore, during the duty drivingperiod following the scanning period, the pixels 10 are not additionallysupplied with the data voltage and are driven at the duty ratio equal toor less than 50%. Hence, data is displayed at the same luminance duringone frame period.

The data driver 102 converts data DATA of the input image received fromthe timing controller 110 into a gamma compensation voltage under thecontrol of the timing controller 110 and generates the data voltage. Thedata driver 102 outputs the data voltage to the data lines 11. The datadriver 102 may output a predetermined reference voltage Vref to the datalines 11 during an initialization period ti, so as to initialize thedriving elements of the pixels 10.

The gate driver 104 supplies the first and second scan pulses SCAN1 andSCAN2 to the first and second scan lines 12 a and 12 b under the controlof the timing controller 110. The first and second scan pulses SCAN1 andSCAN2 are synchronized with the data voltage. When the data voltage issupplied to the pixels, the first scan pulse SCAN1 maintains an on-leveland turns on a switching element T3, thereby selecting the pixels 10 tobe charged with the data voltage. The second scan pulse SCAN2 rises atthe same time as the first scan pulse SCAN1 and falls earlier than thefirst scan pulse SCAN1, thereby initializing the pixels 10 during theinitialization period ti. The second scan pulse SCAN2 rises at the sametime as the first scan pulse SCAN1 and falls before a sampling periodts.

The gate driver 104 shifts the scan pulses SCAN1 and SCAN2 using a shiftregister and sequentially supplies the scan pulses SCAN1 and SCAN2 tothe scan lines 12 a and 12 b. The shift register of the gate driver 104may be directly formed on the substrate of the display panel along withthe pixel array AA through a gate-in panel (GIP) process.

The EM driver 106 is a duty driver that outputs the EM signal EM underthe control of the timing controller 110 and supplies the EM signal EMto the EM signal lines 12 c. The EM driver 106 shifts the EM signal EMusing a shift register and sequentially supplies the EM signal EM to theEM signal lines 12 c. The EM driver 106 repeatedly toggles the EM signalEM during the duty driving period under the control of the timingcontroller 110 and drives the pixels 10 at a duty ratio equal to or lessthan 50%. The shift register of the EM driver 106 may be directly formedon the substrate of the display panel along with the pixel array AAthrough the GIP process.

The timing controller 110 receives digital video data DATA of the lefteye image and the right eye image received from the main board 14 and atiming signal synchronized with the digital video data DATA. The timingsignal includes a vertical sync signal Vsync, a horizontal sync signalHsync, a clock signal CLK and a data enable signal DE. The timingcontroller 110 generates a data timing control signal for controllingoperation timing of the data driver 102, a gate timing control signalfor controlling operation timing of the gate driver 104, and a dutytiming control signal for controlling operation timing of the EM driver106 based on the timing signal received from the main board 14 and apredetermined register setting value. The timing controller 110 controlsa duty ratio of the EM signal EM using the duty timing control signal.

As shown in FIG. 8, each pixel 10 includes an OLED, a plurality of thinfilm transistors (TFTs) T1 to T4, and a storage capacitor Cst. Acapacitor C may be connected between a drain of the second TFT T2 and asecond node B. In FIG. 8, “Coled” denotes a parasitic capacitance of theOLED. The TFTs are implemented as the n-type MOSFET. During the scanningperiod, the pixels 10 sample a threshold voltage of the driving elementT1 and are supplied with the data voltage of the input image. During aduty driving period tem, the pixels 10 emit light at a duty ratio equalto or less than 50%. The scanning period is divided into theinitialization period ti, in which the pixels 10 are initialized, thesampling period ts, in which the threshold voltage of the drivingelement of each pixel 10 is sampled, and a programming period tw, inwhich the data voltage of the input image is supplied to the pixels 10.

The OLED emits light using an amount of current controlled by the firstTFT T1 depending on the data voltage output from the data driver 102. Acurrent path of the OLED is switched by the second TFT T2. The OLEDincludes an organic compound layer formed between an anode and acathode. The organic compound layer may include a hole injection layerHIL, a hole transport layer HTL, an emission layer EML, an electrontransport layer ETL, and an electron injection layer EIL, but is notlimited thereto. The anode of the OLED is connected to the second nodeB, and the cathode of the OLED is connected to a VSS electrode, to whicha low potential power voltage or a ground level voltage VSS is applied.“Coled” denotes a parasitic capacitance formed between the anode and thecathode of the OLED.

The first TFT T1 is a driving element adjusting a current flowing in theOLED depending on a gate-to-source voltage Vgs. The first TFT T1includes a gate connected to a first node A, a drain connected to asource of the second TFT T2, and a source connected to the second nodeB.

The second TFT T2 is a switching element switching a current flowing inthe OLED in response to the EM signal EM. The EM signal EM is generatedat an on-level during the sampling period ts and repeats the on-leveland an off-level during the duty driving period. Hence, the EM signal EMis generated at a duty ratio equal to or less than 50%. The drain of thesecond TFT T2 is connected to the VDD line supplied with the highpotential driving voltage VDD, and the source of the second TFT T2 isconnected to the drain of the first TFT T1. A gate of the second TFT T2is connected to the EM signal line 12 c and is supplied with the EMsignal EM. The EM signal EM is generated at the on-level (or a highlogic level) during the sampling period ts and turns on the second TFTT2. The EM signal EM is inverted to the off-level (or a low logic level)during the initialization period ti and the programming period tw andturns off the second TFT T2. The EM signal EM repeats the on-level andthe off-level depending on a pulse width modulation (PWM) duty ratio andis generated at a duty ratio equal to or less than 50% during the dutydriving period tem. The OLED emits light at a duty ratio equal to orless than 50% due to the second TFT T2 switching in response to the EMsignal EM.

The third TFT T3 is a switching element supplying the data voltage Vdatato the first node A in response to the first scan pulse SCAN1. The thirdTFT T3 includes a gate connected to the first scan line 12 a, a drainconnected to the data line 11, and a source connected to the first nodeA. The first scan pulse SCAN1 is supplied to the pixels 10 through thefirst scan line 12 a. The first scan pulse SCAN1 is generated at anon-level during about one horizontal period 1H and turns on the thirdTFT T3. The first scan pulse SCAN1 is inverted to an off-level duringthe duty driving period tem and turns off the third TFT T3.

The fourth TFT T4 is a switching element supplying the reference voltageVref to the second node B in response to the second scan pulse SCAN2.The fourth TFT T4 includes a gate connected to the second scan line 12b, a drain connected to the REF line 16, and a source connected to thesecond node B. The second scan pulse SCAN2 is supplied to the pixels 10through the second scan line 12 b. The second scan pulse SCAN2 isgenerated at an on-level during the initialization period ti and turnson the fourth TFT T4. The second scan pulse SCAN2 maintains an off-levelduring the remaining period and controls the fourth TFT T4 in anOff-state.

The storage capacitor Cst is connected between the first node A and thesecond node B and stores a difference voltage between the first node Aand the second node B, thereby holding the gate-to-source voltage Vgs ofthe first TFT T1. The storage capacitor Cst samples a threshold voltageVth of the driving element, i.e., the first TFT T1 in a source followermanner. The capacitor C is connected between the VDD line and the secondnode B. When a voltage of the first node A changes depending on the datavoltage Vdata during the programming period tw, the capacitors Cst and Cdivide a change amount of the voltage of the first node A and reflectthe divided voltage on a voltage of the second node B.

The scanning period of the pixel 10 is divided into the initializationperiod ti, the sampling period ts, and the programming period tw. Thescanning period is set to about one horizontal period 1H, and data iswritten on the pixels 10 arranged on one horizontal line of the pixelarray during the scanning period. During the scanning period, thethreshold voltage Vth of the driving element, i.e., the first TFT T1 ofthe pixel 10 is sampled, and the data voltage is compensated by anamount of the threshold voltage Vth. Thus, during one horizontal period1H, data DATA of the input image is compensated by an amount of thethreshold voltage Vth of the driving element T1 and is written on thepixel 10.

When the initialization period ti starts, the first and second scanpulses SCAN1 and SCAN2 rise and are generated at the on-level. And atthe same time, the EM signal EM falls and changes to the off-level.During the initialization period ti, the second TFT T2 is turned off andblocks a current path of the OLED. During the initialization period ti,the third and fourth TFTs T3 and T4 are turned on. During theinitialization period ti, the predetermined reference voltage Vref issupplied to the data line 11. During the initialization period ti, thevoltage of the first node A is initialized to the reference voltageVref, and the voltage of the second node B is initialized to thepredetermined initialization voltage Vini. After the initializationperiod ti, the second scan pulse SCAN2 changes to the off-level andturns off the fourth TFT T4. The on-level is a level of a gate voltageof the TFT that causes the switching elements T2 to T4 of the pixel 10to be turned on. The off-level is a level of the gate voltage of the TFTthat causes the switching elements T2 to T4 of the pixel 10 to be turnedoff.

During the sampling period ts, the first scan pulse SCAN1 maintains theon-level, and the second scan pulse SCAN2 maintains the off-level. Whenthe sampling period ts starts, the EM signal EM rises and changes to theon-level. During the sampling period ts, the second and third TFTs T2and T3 are turned on. During the sampling period ts, the second TFT T2is turned on in response to the EM signal EM of the on-level. During thesampling period ts, the third TFT T3 maintains the On-state due to thefirst scan pulse SCAN1 of the on-level. During the sampling period ts,the reference voltage Vref is supplied to the data line 11. During thesampling period ts, the voltage of the first node A is held at thereference voltage Vref, and the voltage of the second node B rises dueto a drain-to-source current Ids. The gate-to-source voltage Vgs of thefirst TFT T1 is sampled as the threshold voltage Vth of the first TFT T1through the source follower manner, and the sampled threshold voltageVth is stored in the storage capacitor Cst. During the sampling periodts, the voltage of the first node A is the reference voltage Vref, andthe voltage of the second node B is “Vref-Vth”.

During the programming period tw, the third TFT T3 maintains theOn-state in response to the first scan pulse SCAN1 of the on-level, andthe remaining TFTs T1, T2, and T4 are turned off. During the programmingperiod tw, the data voltage Vdata of the input image is supplied to thedata line 11. The data voltage Vdata is applied to the first node A, andthe result of voltage division between the capacitors Cst and C withrespect to a change amount (Vdata−Vref) of the voltage of the first nodeA is reflected on the voltage of the second node B. Hence, thegate-to-source voltage Vgs of the first TFT T1 is programmed. During theprogramming period tw, the voltage of the first node A is the datavoltage Vdata, and the voltage of the second node B is“Vref−Vth+C′*(Vdata−Vref)” obtained by adding the result(C′*(Vdata−Vref)) of voltage division between the capacitors Cst and Cto the voltage “Vref-Vth” set through the sampling period ts. As aresult, the gate-to-source voltage Vgs of the first TFT T1 is programmedto “Vdata−Vref+Vth−C′*(Vdata−Vref)” through the programming period tw.In the embodiment disclosed herein, C′ is Cst/(Cst+C).

When the duty driving period tem starts, the EM signal EM rises andagain changes to the on-level. On the other hand, the first scan pulseSCAN1 falls and changes to the off-level. During the duty driving periodtem, the second TFT T2 maintains the On-state and forms a current pathof the OLED. During the duty driving period tem, the first TFT T1controls an amount of current flowing in the OLED based on the datavoltage Vdata.

The duty driving period tem ranges from termination point of theprogramming period tw to a start point of the initialization period tiof a next frame period. The embodiment of the invention causes thepixels 10 not to successively emit light during the duty driving periodtem and causes the pixels 10 to emit light at a duty ratio equal to orless than 50% through the switching of the EM signal EM. When the EMsignal EM is generated at the on-level, the second TFT T2 is turned onand forms the current path of the OLED. During the duty driving periodtem, a current Ioled controlled based on the gate-to-source voltage Vgsof the first TFT T1 flows in the OLED and causes the OLED to emit light.During the duty driving period tem, because the first and second scanpulses SCAN1 and SCAN2 maintain the off-level, the third and fourth TFTsT3 and T4 are turned off.

The current Ioled flowing in the OLED during the duty driving period temis expressed by the following Equation 1. The OLED emits light due tothe current Ioled and represents brightness of the input image.

$\begin{matrix}{{I_{oled} = {\begin{matrix}k \\2\end{matrix}\left\lbrack {\begin{pmatrix}1 & 0^{\prime}\end{pmatrix}\begin{pmatrix}V_{data} & \text{?}\end{pmatrix}} \right\rbrack}^{2}}{\text{?}\text{indicates text missing or illegible when filed}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In the above Equation 1, k is a proportional constant determined by amobility, a parasitic capacitance, a channel capacity, etc. of the firstTFT T1.

Because the threshold voltage Vth of the first TFT T1 is included in thegate-to-source voltage Vgs of the first TFT T1 programmed through theprogramming period tw, Vth is cancelled in Ioled expressed inEquation 1. Thus, an influence of the threshold voltage Vth of thedriving element, i.e., the first TFT T1 on the current Ioled of the OLEDis removed.

FIG. 10 is a waveform diagram illustrating a duty driving method of apixel circuit according to the embodiment of the invention. FIG. 11illustrates a BDI effect in a duty driving method of a pixel circuitaccording to the embodiment of the invention. In FIG. 11, (a) shows animage of one frame. (b) of FIG. 11 shows an example where a non-dutydriving period (i.e., turn-off period) is sequentially shifted when thesame image as (a) of FIG. 11 is displayed on the pixels using the dutydriving method. FIG. 12 illustrates a principle, in which data of apixel is maintained during one frame period without additional dataaddressing.

Referring to FIGS. 10 and 11, the vertical sync signal Vsync is a timingsignal defining one frame period. During one frame period, image datacorresponding to an amount of one frame is addressed to the pixels 10and is written on the pixels 10.

Only during an initial scanning period of one frame period, data of aninput image is addressed to the pixels 10 and is written on the pixels10. The pixels 10 are turned off in an off-level period of the EM signalEM. However, as shown in FIG. 9, the pixels 10 hold the data voltage andemit light during a turn-on period after a turn-off period at the sameluminance as a turn-on period before the turn-off period.

An on-level period of the EM signal EM defines a turn-on period in thepixel array. The EM signal EM of the on-level forms the current path ofthe OLED in the pixels 10 and turns on the OLED. On the other hand, theoff-level period of the EM signal EM defines a turn-off period in thepixel array. During the turn-off period, the EM signal EM of theoff-level is applied to the pixels 10. The pixels 10 of the turn-offperiod display a black gray level because the current path of the OLEDis blocked and the current does not flow in the OLED.

The EM signal EM has two or more cycles during the duty driving periodtem of one frame period. One cycle of the EM signal EM includes oneon-level period and one off-level period. Thus, the on-level periods andthe off-level periods of the EM signal EM alternate with each otherduring the duty driving period tem, and the adjacent on-level periodsare cut off with the off-level period interposed therebetween. Eachpixel 10 is turned off due to the EM signal EM one or more times in theduty driving period tem. Because the off-level period of the EM signalEM is shifted along a scanning direction of the display panel, theturn-off period in the pixel array AA is shifted along the off-levelperiod of the EM signal EM as shown in FIG. 10.

The duty driving method drives the pixels 10 at a duty ratio equal to orless than 50% and thus can improve the image retention and the flicker.In particular, the duty driving method can reduce the user's fatiguewhen the personal immersive device displays the 3D motion picture.

The embodiment of the invention holds the data voltage of the pixelsduring the duty driving period without additionally writing data on thepixels. This is described with reference to FIG. 12.

Referring to FIG. 12, after data is written on the pixels 10 through thedata addressing, the first scan pulse SCAN1 maintains the off-levelduring one frame period. As a result, after the storage capacitor Cst ischarged with the data voltage, the first node A connected to the gate ofthe first TFT T1 is floated. When a source voltage Vs of the first TFTT1 changes, the gate voltage Vg changes depending on a change in thesource voltage Vs while charges of the storage capacitor Cst areuniformly maintained. As a result, after the pixels 10 are turned offdue to the on-level period and the off-level period of the EM signal EM,the gate-to-source voltage Vgs of the driving element, i.e., the firstTFT T1 may be uniformly held even if data is not again written on thepixels 10. Because the gate-to-source voltage Vgs of the driving elementT1 is uniformly held as described above, the data written on the pixels10 is maintained.

Next, the pixel arrays of the first and second display panels of thedisplay device for the personal immersive device according to theembodiment of the invention are described.

FIGS. 13A to 15B illustrate examples of configuration of the pixelarrays of the first and second display panels of the display device forthe personal immersive device according to the embodiment of theinvention.

As shown in FIGS. 13A to 15B, each unit pixel of a pixel array of afirst OLED display panel PNL1 of the personal immersive device accordingto the embodiment of the invention includes two subpixels from thefollowing group of subpixels: a red (R) subpixel, a green (G) subpixel,and a blue (B) subpixel. Further, a first unit pixel among adjacent unitpixels includes a subpixel of the same color as any one of subpixelsincluded in a second unit pixel adjacent to the first unit pixel and asubpixel of a color not included in the second unit pixel. Each unitpixel of a pixel array of a second OLED display panel PNL2 includes twosubpixels from the following group of subpixels: R, G, and B subpixels.The second display panel PNL2 also includes a third unit pixelcorresponding to the first unit pixel of PNL1 and a fourth unit pixelcorresponding to the second unit pixel of PNL1. The first unit pixel hasthe same subpixel arrangement as the fourth unit pixel, and the secondunit pixel has the same subpixel arrangement as the third unit pixel.

According to the structures of the pixel array according to theembodiment of the invention, a color absent in a unit pixel of each ofthe first and second display panels is disposed in another unit pixeladjacent to the unit pixel, and a color of a unit pixel of a left eyeimage is different from a color of a corresponding unit pixel of a righteye image. Therefore, when the left eye image and the right eye imageare combined, all of colors are represented on each unit pixel. Hence,the embodiment of the invention can increase the pixel density of thecolor while maintaining a resolution of the display device.

Hereinafter, configuration of the pixel arrays of the first and seconddisplay panels of the display device for the personal immersive deviceaccording to the embodiment of the invention is described in detail withreference to FIGS. 13A to 15B.

FIG. 13A shows a first example of pixel arrays of the first and seconddisplay panels PNL1 and PNL2 of the display device for the personalimmersive device according to the embodiment of the invention. FIG. 13Billustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel array of FIG. 13A.

Referring to FIG. 13A, each pixel row of the first display panel PNL1 isaligned with a corresponding pixel row of the second display panel PNL2in the X direction. For example, the first pixel row of the firstdisplay panel PNL1 and the first pixel row of the second display panelPNL2 are aligned with each other in the X direction. Each pixel row inthe first display panel PNL1 includes a left end LE1 and a right endRE1. The right end RE1 is closer to the second display panel PNL2 thanleft end LE1. Each pixel row in the second display panel PNL2 includes aleft end LE2 and a right end RE2. The right end RE2 is located furtherfrom first display panel PNL1 than left end LE2.

Additionally, two unit pixel types are mixed together and alternate witheach other in the display panels. One type of unit pixel includes R andB subpixels but no G subpixels. Another type of unit pixel includes Gand B subpixels but no R subpixels. A first row of the first displaypanel PNL1 repeats an arrangement where R, B, G, and B subpixels formtwo unit pixels. As a result, the first row of display panel PNL1includes an alternating RB-GB unit pixel arrangement. A second row ofthe first display panel PNL1 repeats an arrangement where G, B, R, and Bsubpixels form two unit pixels. As a result, the second row of displaypanel PNL1 includes an alternating GB-RB unit pixel arrangement. In thefirst display panel PNL1, odd-numbered rows (for example, a third row)repeat the same arrangement as the first row, and even-numbered rows(for example, a fourth row) repeat the same arrangement as the secondrow.

Further, a first row of the second display panel PNL2 repeats anarrangement where G, B, R, and B subpixels form two unit pixels. As aresult, the first row of display panel PNL2 includes the alternatingGB-RB unit pixel arrangement. A second row of the second display panelPNL2 repeats an arrangement where R, B, G, and B subpixels form two unitpixels. As a result, the second row of display panel PNL2 includes thealternating RB-GB unit pixel arrangement.

Alternatively, the first row of the first display panel PNL1 may repeatan arrangement where G, B, R, and B subpixels form two unit pixels, anda second row of the first display panel PNL1 may repeat an arrangementwhere R, B, G, and B subpixels form two unit pixels. In the firstdisplay panel PNL1, the odd-numbered rows may repeat the samearrangement as the first row, and the even-numbered rows may repeat thesame arrangement as the second row.

In this instance, the first row of the second display panel PNL2 mayrepeat an arrangement where R, B, G, and B subpixels form two unitpixels, and the second row of the second display panel PNL2 may repeatan arrangement where G, B, R, and B subpixels form two unit pixels.

According to the first example of the pixel array structure according tothe embodiment of the invention, two adjacent unit pixels disposed onthe first pixel row of the first display panel PNL1 include a 1-1 unitpixel including the R and B subpixels at the left end LE1 of the firstpixel row and a 1-2 unit pixel including the G and B subpixels. Twoadjacent unit pixels disposed on the second row includes a 1-3 unitpixel including the G and B subpixels, and a 1-4 unit pixel includingthe R and B subpixels. The 1-3 unit pixel is in a same pixel column asthe 1-1 unit pixel, and the 1-4 unit pixel is in a same pixel column asthe 1-2 unit pixel.

Accordingly, the green color absent in the 1-1 unit pixel can becompensated with the G subpixel disposed in the 1-2 unit pixel adjacentto the 1-1 unit pixel, and the red color absent in the 1-2 unit pixelcan be compensated with the R subpixel disposed in the 1-1 unit pixeladjacent to the 1-2 unit pixel. Further, the red color absent in the 1-3unit pixel can be compensated with the R subpixel disposed in the 1-4unit pixel adjacent to the 1-3 unit pixel, and the green color absent inthe 1-4 unit pixel can be compensated with the G subpixel disposed inthe 1-3 unit pixel adjacent to the 1-4 unit pixel.

Further, two adjacent unit pixels disposed on the first row of thesecond display panel PNL2 include a 2-1 unit pixel including the G and Bsubpixels at the left end LE2 of the row and a 2-2 unit pixel includingthe R and B subpixels. Two adjacent unit pixels disposed on the secondrow includes a 2-3 unit pixel including the R and B subpixels and a 2-4unit pixel including the G and B subpixels. The 2-3 unit pixel is in asame pixel column as the 2-1 unit pixel, and the 2-4 unit pixel is in asame pixel column as the 2-2 unit pixel.

Accordingly, the red color absent in the 2-1 unit pixel can becompensated with the R subpixel disposed in the 2-2 unit pixel adjacentto the 2-1 unit pixel, and the green color absent in the 2-2 unit pixelcan be compensated with the G subpixel disposed in the 2-1 unit pixeladjacent to the 2-2 unit pixel. Further, the green color absent in the2-3 unit pixel can be compensated with the G subpixel disposed in the2-4 unit pixel adjacent to the 2-3 unit pixel, and the red color absentin the 2-4 unit pixel can be compensated with the R subpixel disposed inthe 2-3 unit pixel adjacent to the 2-4 unit pixel.

The left eye image displayed on the first display panel PNL1 and theright eye image displayed on the second display panel PNL2 arerespectively input through the left eye and the right eye and arecombined in the brain. As a result, as shown in FIG. 13B, all of theunit pixels can represent the red, green, and blue colors through acombination of the 1-1 unit pixel (including the R and B subpixels) andthe 2-1 unit pixel (including the G and B subpixels), a combination ofthe 1-2 unit pixel (including the G and B subpixels) and the 2-2 unitpixel (including the R and B subpixels), a combination of the 1-3 unitpixel (including the G and B subpixels) and the 2-3 unit pixel(including the R and B subpixels), and a combination of the 1-4 unitpixel (including the R and B subpixels) and the 2-4 unit pixel(including the G and B subpixels).

Accordingly, the first example of the pixel array structure according tothe embodiment of the invention can increase the pixel density of thecolor while maintaining the resolution of the display device.

FIG. 14A shows a second example of pixel arrays of the first and seconddisplay panels PNL1 and PNL2 of the display device for the personalimmersive device according to the embodiment of the invention. FIG. 14Billustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel array of FIG. 14A.

Referring to FIG. 14A, the pixel arrays are similar to those shown inFIG. 13A, but now include different repeating pixel arrangements. Twotypes of unit pixels are mixed together in the panels. One type of unitpixel includes R and G subpixels but no B subpixels. Another type ofunit pixel includes B and G subpixels but no R subpixels.

A first row of the first display panel PNL1 repeats an arrangement whereR, G, B, and G subpixels form two unit pixels. As a result, the firstrow of display panel PNL1 includes an alternating RG-BG unit pixelarrangement. A second row of the first display panel PNL1 repeats anarrangement where B, G, R, and G subpixels form two unit pixels. As aresult, the second row of display panel PNL1 includes an alternatingBG-RG unit pixel arrangement. In the first display panel PNL1,odd-numbered rows (for example, a third row) repeat the same arrangementas the first row, and even-numbered rows (for example, a fourth row)repeat the same arrangement as the second row.

Further, a first row of the second display panel PNL2 repeats anarrangement where B, G, R, and G subpixels form two unit pixels. As aresult, the first row of display panel PNL2 includes the alternatingBG-RG unit pixel arrangement. A a second row of the second display panelPNL2 repeats an arrangement where R, G, B, and G subpixels form two unitpixels. As a result, the second row of display panel PNL2 includes thealternating RG-BG pixel unit arrangement.

Alternatively, the first row of the first display panel PNL1 may repeatan arrangement where R, G, B and G subpixels form two unit pixels, and asecond row of the first display panel PNL1 may repeat an arrangementwhere B, G, R and G subpixels form two unit pixels. In the first displaypanel PNL1, the odd-numbered rows may repeat the same arrangement as thefirst row, and the even-numbered rows may repeat the same arrangement asthe second row.

In this instance, the first row of the second display panel PNL2 mayrepeat an arrangement where B, G, R and G subpixels form two unitpixels, and the second row of the second display panel PNL2 may repeatan arrangement where R, G, B and G subpixels form two unit pixels.

According to the second example of the pixel array structure accordingto the embodiment of the invention, two adjacent unit pixels disposed onthe first pixel row of the first display panel PNL1 include a 1-1 unitpixel including the R and G subpixels at the left end LE1 of the firstpixel row and a 1-2 unit pixel including the B and G subpixels, and twoadjacent unit pixels disposed on the second row includes a 1-3 unitpixel including the B and G subpixels and a 1-4 unit pixel including theR and G subpixels.

Accordingly, the blue color absent in the 1-1 unit pixel can becompensated with the B subpixel disposed in the 1-2 unit pixel adjacentto the 1-1 unit pixel, and the red color absent in the 1-2 unit pixelcan be compensated with the R subpixel disposed in the 1-1 unit pixeladjacent to the 1-2 unit pixel. Further, the red color absent in the 1-3unit pixel can be compensated with the R subpixel disposed in the 1-4unit pixel adjacent to the 1-3 unit pixel, and the blue color absent inthe 1-4 unit pixel can be compensated with the B subpixel disposed inthe 1-3 unit pixel adjacent to the 1-4 unit pixel.

Further, two adjacent unit pixels disposed on the first row of thesecond display panel PNL2 include a 2-1 unit pixel including the B and Gsubpixels at the left end LE2 of the row and a 2-2 unit pixel includingthe R and G subpixels. Two adjacent unit pixels disposed on the secondrow includes a 2-3 unit pixel including the R and G subpixels and a 2-4unit pixel including the B and G subpixels.

Accordingly, the red color absent in the 2-1 unit pixel can becompensated with the R subpixel disposed in the 2-2 unit pixel adjacentto the 2-1 unit pixel, and the blue color absent in the 2-2 unit pixelcan be compensated with the B subpixel disposed in the 2-1 unit pixeladjacent to the 2-2 unit pixel. Further, the blue color absent in the2-3 unit pixel can be compensated with the B subpixel disposed in the2-4 unit pixel adjacent to the 2-3 unit pixel, and the red color absentin the 2-4 unit pixel can be compensated with the R subpixel disposed inthe 2-3 unit pixel adjacent to the 2-4 unit pixel.

The left eye image displayed on the first display panel PNL1 and theright eye image displayed on the second display panel PNL2 arerespectively input through the left eye and the right eye and arecombined in the brain. As a result, as shown in FIG. 14B, all of theunit pixels can represent the red, green, and blue colors through acombination of the 1-1 unit pixel (including the R and G subpixels) andthe 2-1 unit pixel (including the B and G subpixels), a combination ofthe 1-2 unit pixel (including the B and G subpixels) and the 2-2 unitpixel (including the R and G subpixels), a combination of the 1-3 unitpixel (including the B and G subpixels) and the 2-3 unit pixel(including the R and G subpixels), and a combination of the 1-4 unitpixel (including the R and G subpixels) and the 2-4 unit pixel(including the B and G subpixels).

Accordingly, the second example of the pixel array structure accordingto the embodiment of the invention can increase the pixel density of thecolor while maintaining the resolution of the display device.

FIG. 15A shows a third example of pixel arrays of the first and seconddisplay panels PNL1 and PNL2 of the display device for the personalimmersive device according to the embodiment of the invention. FIG. 15Billustrates an arrangement of colors obtained by combining andrecognizing a left eye image and a right eye image in a brain inaccordance with configuration of the pixel array of FIG. 15A.

Referring to FIG. 15A, the pixel arrays are similar to those shown inFIGS. 13A and 14A, but now include different repeating pixelarrangements. Two types of unit pixels are mixed together in the panels.One type of unit pixel includes G and R subpixels but no B subpixels.Another type of unit pixel includes B and R subpixels but no Gsubpixels.

A first row of the first display panel PNL1 repeats an arrangement whereG, R, B, and R subpixels form two unit pixels. As a result, the firstrow of display panel PNL1 includes an alternating GR-BR unit pixelarrangement. A second row of the first display panel PNL1 repeats anarrangement where B, R, G, and R subpixels form two unit pixels. As aresult, the second row of display panel PNL1 includes an alternatingBR-GR unit pixel arrangement. In the first display panel PNL1,odd-numbered rows (for example, a third row) repeat the same arrangementas the first row, and even-numbered rows (for example, a fourth row)repeat the same arrangement as the second row.

Further, a first row of the second display panel PNL2 repeats anarrangement where B, R, G, and R subpixels form two unit pixels. As aresult, the first row of display panel PNL2 includes the alternatingBR-GR pixel arrangement. A second row of the second display panel PNL2repeats an arrangement where G, R, B, and R subpixels form two unitpixels. As a result, the second row of display panel PNL2 includes thealternating GR-BR pixel arrangement.

Alternatively, the first row of the first display panel PNL1 may repeatan arrangement where B, R, G, and R subpixels form two unit pixels, anda second row of the first display panel PNL1 may repeat an arrangementwhere G, R, B, and R subpixels form two unit pixels. In the firstdisplay panel PNL1, the odd-numbered rows may repeat the samearrangement as the first row, and the even-numbered rows may repeat thesame arrangement as the second row.

In this instance, the first row of the second display panel PNL2 mayrepeat an arrangement where G, R, B, and R subpixels form two unitpixels, and the second row of the second display panel PNL2 may repeatan arrangement where B, R, G, and R subpixels form two unit pixels.

According to the third example of the pixel array structure according tothe embodiment of the invention, two adjacent unit pixels disposed onthe first pixel row of the first display panel PNL1 include a 1-1 unitpixel including the G and R subpixels at the left end LE1 of the firstpixel row and a 1-2 unit pixel including the B and R subpixels, and twoadjacent unit pixels disposed on the second row includes a 1-3 unitpixel including the B and R subpixels and a 1-4 unit pixel including theG and R subpixels.

Accordingly, the blue color absent in the 1-1 unit pixel can becompensated with the B subpixel disposed in the 1-2 unit pixel adjacentto the 1-1 unit pixel, and the green color absent in the 1-2 unit pixelcan be compensated with the G subpixel disposed in the 1-1 unit pixeladjacent to the 1-2 unit pixel. Further, the green color absent in the1-3 unit pixel can be compensated with the G subpixel disposed in the1-4 unit pixel adjacent to the 1-3 unit pixel, and the blue color absentin the 1-4 unit pixel can be compensated with the B subpixel disposed inthe 1-3 unit pixel adjacent to the 1-4 unit pixel.

Further, two adjacent unit pixels disposed on the first row of thesecond display panel PNL2 include a 2-1 unit pixel including the B and Rsubpixels at the left end LE2 of the first pixel row and a 2-2 unitpixel including the G and R subpixels, and two adjacent unit pixelsdisposed on the second row includes a 2-3 unit pixel including the G andR subpixels and a 2-4 unit pixel including the B and R subpixels.

Accordingly, the green color absent in the 2-1 unit pixel can becompensated with the G subpixel disposed in the 2-2 unit pixel adjacentto the 2-1 unit pixel, and the blue color absent in the 2-2 unit pixelcan be compensated with the B subpixel disposed in the 2-1 unit pixeladjacent to the 2-2 unit pixel. Further, the blue color absent in the2-3 unit pixel can be compensated with the B subpixel disposed in the2-4 unit pixel adjacent to the 2-3 unit pixel, and the green colorabsent in the 2-4 unit pixel can be compensated with the G subpixeldisposed in the 2-3 unit pixel adjacent to the 2-4 unit pixel.

The left eye image displayed on the first display panel PNL1 and theright eye image displayed on the second display panel PNL2 arerespectively input through the left eye and the right eye and arecombined in the brain. As a result, as shown in FIG. 15B, all of theunit pixels can represent the red, green, and blue colors through acombination of the 1-1 unit pixel (including the G and R subpixels) andthe 2-1 unit pixel (including the B and R subpixels), a combination ofthe 1-2 unit pixel (including the B and R subpixels) and the 2-2 unitpixel (including the G and R subpixels), a combination of the 1-3 unitpixel (including the B and R subpixels) and the 2-3 unit pixel(including the G and R subpixels), and a combination of the 1-4 unitpixel (including the G and R subpixels) and the 2-4 unit pixel(including the B and R subpixels).

Accordingly, the third example of the pixel array structure according tothe embodiment of the invention can increase the pixel density of thecolor while maintaining the resolution of the display device.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the scope of the principles of thisdisclosure. For example, in the embodiments of the invention, thearrangement of the unit pixels of the first pixel array and thearrangement of the unit pixels of the second pixel array may beconfigured to have a mirror-image relationship. Thus, various variationsand modifications are possible in the component parts and/orarrangements of the subject combination arrangement within the scope ofthe disclosure, the drawings and the appended claims.

What is claimed is:
 1. A display device for virtual reality, the displaydevice comprising: a first display panel for displaying an image for aleft eye; and a second display panel for displaying an image for a righteye, wherein the first display panel comprises a first pixel row havinga first end and a second end that is closer to the second display panelthan the first end, the first pixel row having a first arrangement ofunit pixels that alternate between a first unit pixel type and a secondunit pixel type, the first unit pixel type comprising subpixels of afirst color and a second color but not a third color, and the secondunit pixel type comprises subpixels of the third color and the secondcolor but not the first color, wherein the second display panelcomprises a second pixel row aligned with the first pixel row and havinga third end and a fourth end that is further from the first displaypanel than the third end, the second pixel row having a secondarrangement of unit pixels that alternate between the second unit pixeltype and the first unit pixel type, wherein a first unit pixel at thefirst end of the first pixel row is the first unit pixel type, and asecond unit pixel at the third end of the second pixel row is the secondunit pixel type.
 2. The display device of claim 1, wherein the firstunit pixel type comprises subpixels of a red color and a blue color butnot a green color, and the second unit pixel type comprises subpixels ofthe green color and the blue color but not the red color.
 3. The displaydevice of claim 1, wherein the first unit pixel type comprises subpixelsof a red color and a green color but not a blue color, and the secondunit pixel type comprises subpixels of the blue color and the greencolor but not the red color.
 4. The display device of claim 1, whereinthe first unit pixel type comprises subpixels of a green color and a redcolor but not a blue color, and the second unit pixel type comprisessubpixels of the blue color and the red color but not the green color.5. The display device of claim 1, wherein the first display panelcomprises a third pixel row having the second arrangement of unitpixels, the third pixel row having a third unit pixel of the second unitpixel type, the third unit pixel in a same pixel column as the firstunit pixel of the first pixel row; and the second display panelcomprises a fourth pixel row having the first arrangement of unitpixels, the fourth pixel row having a fourth unit pixel of the firstunit pixel type, the fourth unit pixel in a same pixel column as thesecond unit pixel of the second pixel row.
 6. A display device forvirtual reality, the display device comprising: a first display panelfor displaying an image for a left eye; and a second display panel fordisplaying an image for a right eye, the first display panel and thesecond display panel both having a mix of unit pixels that include afirst unit pixel type and a second unit pixel type, the first unit pixeltype comprising subpixels of a first color and a second color but not athird color, and the second unit pixel type comprising subpixels of thethird color and the second color but not the first color wherein thefirst display panel comprises a first pixel row having a first end and asecond end that is closer to the second display panel than the firstend, wherein the second display panel comprises a second pixel rowaligned with the first pixel row and having a third end and a fourth endthat is further from the first display panel than the third end, whereina first unit pixel at the first end of the first pixel row is the firstunit pixel type, and a second unit pixel at the third end of the secondpixel row is the second unit pixel type.
 7. The display device of claim6, wherein the first unit pixel type comprises subpixels of a red colorand a blue color but not a green color, and the second unit pixel typecomprises subpixels of the green color and the blue color but not thered color.
 8. The display device of claim 6, wherein the first unitpixel type comprises subpixels of a red color and a green color but nota blue color, and the second unit pixel type comprises subpixels of theblue color and the green color but not the red color.
 9. The displaydevice of claim 6, wherein the first unit pixel type comprises subpixelsof a green color and a red color but not a blue color, and the secondunit pixel type comprises subpixels of the blue color and the red colorbut not the green color.
 10. The display device of claim 6, wherein thefirst display panel comprises a third pixel row having a third unitpixel of the second unit pixel type, the third unit pixel in a samepixel column as the first unit pixel of the first pixel row; and thesecond display panel comprises a fourth pixel row having a fourth unitpixel of the first unit pixel type, the fourth unit pixel in a samepixel column as the second unit pixel of the second pixel row.